OPTICAL FILTER, OPTICAL DEVICE, ELECTRONIC DEVICE, AND ANTIREFLECTION COMPLEX

摘要

Provided is an optical filter or an antireflection complex having a thin film with a refractive index gradient (12), the refractive index of which varies continuously and periodically in the film thickness direction, and a fine periodic structure (111) for reducing reflection, on a substrate (13). The optical filter or the antireflection complex, wherein the refractive index of the thin film with a refractive index gradient (12) varies in the film thickness direction in such as manner as approach the refractive index of the substrate (13) on the substrate side (13), and varies in the film thickness direction in such a manner as to approach the refractive index of the fine periodic structure (111) on the fine periodic structure (111) side, is capable of reducing reflection to a greater extent than those of the prior art. The optical filter can be used in optical devices and electronic device displays.